Despite all the talk about the swelling ranks of people with dementia in Japan and what to do with them, there has been little discussion so far about housing designs that meet their needs.

But a care home recently built by major developer Tokyu Land Corp. in Tokyo’s Setagaya Ward could turn the tide. It aims to harness the power of design to help people with dementia keep their independence longer and maintain their dignity better.

For its Setagaya Nakamachi project, a care home and adjacent condos, the developer enlisted the help of the Dementia Services Development Centre at the University of Stirling in Britain, which has researched “dementia-friendly” building design for more than 25 years. The 75-unit care home is the first project outside the U.K. to be accredited by the organization.

Lesley Palmer, the DSDC’s chief architect, said during a media preview of the property last week that designing a dementia-friendly home begins with understanding the symptoms of the illness and the impairments it can cause.

Dementia, for example, involves memory loss, especially about recent events. It can also impair learning and reasoning ability, while causing high levels of stress, she said.

Many people with dementia also have problems with perception and difficulty adjusting to the sensory and mobility impairments brought on by normal aging.

Changes in vision are another challenge. As people age, their visual acuity diminishes and peripheral visual field narrows. They gradually lose their perception of blue and purple colors, as well as sensitivity to color contrast and depth perception, according to Palmer.

Designers must take all of this into consideration, Palmer said, explaining specific recommendations the DSDC has come up with.

“We aim for the built environment to reduce stress and anxiety both for a person with dementia and also those caring for and loving them,” Palmer said. “Buildings and spaces should be designed to be intimate and have a domestic feel. The design should be legible, or intelligible — easy to understand.”

The Setagaya residence features red handrails throughout its interiors — in the corridors, doors and inside the bathroom, which contrast with cream-colored walls. By using the same color, users can identify the rails’ presence and function at a glance. To give residents multiple cues to find their way, signs feature not only words but also pictures.

The layout and design of toilets is key. The bathroom in a resident’s bedroom should be visible from both sitting and lying positions on the bed to ensure easy access. Toilet furnishings should also have a high contrast in colors to help prevent incontinence as well as tripping and falls, Palmer said.

“A white-colored pan against a white-tile toilet floor and a white wall is almost impossible for persons with dementia to see,” she said. “By providing contrast between the sanitary ware and the floor below we can enhance the user’s experience of the toilet and increase the ability to do so independently.”

Elsewhere, the stone floor of the entrance area and the carpet inside should feature similar tones in color. A difference in tones can lead people with visual challenges to think there’s a gap or hole between them, she said.

Light reflectance value, or the amount of light the surface reflects that is expressed in levels 0 (black) to 100 (pure white), needs to be considered when choosing housing materials, Palmer added. For people with visual impairment, different colors such as orange and yellow can appear similar if they reflect light at the same rate, she said.

The need for dementia-friendly housing cannot be overemphasized as Japan braces for the massive graying of its population through the 2060s, when 1 in 2.5 people will be over 65, and people with dementia are expected to number 8.5-11.5 million, according to government estimates.

Kanoko Oishi, CEO of Mediva, a Tokyo-based medical consultancy that introduced the DSDC to Tokyu, said Japan faces “an almost insurmountable challenge” as its population aging outpaces others. Mediva will help operate a DSDC-accredited nursing care station at the Setagaya property.

“While other developed nations have experienced population-aging over 100 years or so, Japan is going through it in just 24 years — a quarter of the time that it took in other countries,” Oishi said. “This is a huge stress — it’s like trying to do a long jump without a run-up.”

A Matter of Health is a new weekly series on the latest health research, technology or policy issue in Japan. It appears on Thursdays.

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